Esters of 2-methyl-1, 3-oxazolidine-3-phosphonic acids and of 2-methyl-tetrahydro-1,3-oxazine-3-phosphonic acids, and their preparation



United States ESTERS F z-Mn'mri-i,s-oxAzoLn)lNn-s=rnos- PHONIC ACIDS AND or Z-ME'IHYL-TETIRAHY- DRO-1,3-0XAZHN'E-3-PHOSPHGNIC ACIDS, AND

THEIR PREPARA'HQN Sidney Melamed, Philadelphia, Pa., assignor to Robin & Haas Company, Philadelphia, Pa., a corporation of Delaware No Drawing. Application October 2?,19d4 Serial No. 465,719

' 11 Claims. or. 260244) where n is an integer having a value of 1 or 2, X is oxygen or sulfur, R is hydrogen, an alkyl group of l to 16 carbon atoms, cyclohexyl, vinyl or phenyl, R is hydrogen, methyl or ethyl, R and R (1) are separate groups selected individually from the class consisting of alkyl 7 (including cyclohexyl) or alkenyl groups of 1 to 18 carbon atoms, aryl, haloaryl, alkaryl, or aralkyl groups of 6 to 20 carbon atoms, or (2) together form a single saturated alkylene group of 2 to 3 carbon atoms forming with the -O-P-O linkage a 5- or 6-sided heterocyclic ring.

R and R are preferably the same when they are separate groups but they may be different within the limits of the above definition. l v

Preferred compounds are those in which X is oxygen, R and R are hydrogen and R and R are lower allryl groups having'l to 4 carbon atoms, phenyl or' chloro phenyl. i v y V While the compounds of this invention may be prepared by the reaction of 2-methyl-1,3-oxazolidines or 2 methyl-tetrahydro-1,3-oxazines with disubstituted halogeno-phosphates, such as chlorophosphates or chlorothiophosphates of the Formula II hereinafter, these procedures give poor yields and the products require extensive purification apparently because of the instability of the initial Zme'thyloxazolidines' and Z-methyl-tetrahydroon standing, and exists in the following equilibrium:

atcn

2 l The unsubstituted oxazolidine and the unsubstituted tetrahydrooxazine'analog are too unstable to be isolated. The compounds of this invention are, however, stable compounds. The methyl group in the 2-position apparently contributes to a surprising extent to the stability of the new compounds. Nevertheless, the new compounds are highly reactive under suitable conditions as will be pointed out more particularly hereinafter.

The present invention also provides a process for producing the new esters, in which the isolation and reaction with a Z-methyl-oxazolidine or a 2-methyl-tetrahydro-1,3-

oxazine are avoided. This process produces the new compounds in high yields.

The compounds of this invention are accordingly pref-' erably prepared by the reaction offa disubstituted halo geno-phosphate or halogeno-thiophosphate of Formula II:

2 II R in which Y is chlorine, bromine or fluorine with a vinyloxalkylamine of the Formula III. n1 CH ==CHOCH(R)(CH CH(R)NH in which the symbols have the same definitions as given above.

Surprisingly it hasbeen found that the reaction of one of the phosphates or thiophosphates of Formula Ilwith one of the essentially linear vinyloxyalkylamines of Formula III leads directly to the production of the new cyclic products of this invention. It cannot have been predicted from the known reactions of. such compounds that cyclic products would result from the process, just described. This process produces the new compounds in high yields from readily available raw materials.

The compounds of this invention are characterized by having methyl in the 2-position of the heterocyclic ring,

and at least one hydrogen in the 4-position of said ring,

The conditions of the reactions for the preparation of the compounds of this invention may vary widely. The temperature may be in the range of -10 C. to C. or more. basic acceptor for the hydrogen chloride liberatedwhich may be excess of the amine reactant, a tertiary organic amine such as pyridine, triethylamine or benzyldimethylamine, or, preferably, an inorganic base such as sodium hydroxide, potassium hydroxide, sodium or potassium car-' bonate, lithium hydroxide or carbonate or the like. Should a disubstituted ,fluoroor bromophosphate or fluoroor bromothiophosphate be used, the same acceptors are employed for the hydrogen fluoride or hydro! gen bromide evolved. The reaction is usually effected,

the order of addition may be reversed or both reactants,

may be added together. Thetime of reaction varies from one to twenty-four hours or more, though in general, a

reaction time of one to four hours is sufiicient.

The amines of Formula III that may be used in the operation of this invention arereadily obtained from the reaction of acetylene at pressures of 100 to. 200 lbs/sq. in. gage with an aminoalcohol of Formula IV:

Where the symbols have the definitions given above in the presence of a strong base, such as potassium, by the gen The reaction is effected in the presence of a if eral procedure described by Reppe. Representative of amines of Formula III that may be used are:

CH =CHO CHzCHzNHg CH =CHOCH (CH CH NH CH =CHO CHCH CH NH CH CHOCH CH CH NH CH CHOCH C H cH NH CH =CHOCH CH H NH CH CHO CH (CH CH) CH NH CH =CHOCH(C H CH2NH2 CH =CHOCH (C H CH NH cgH q CHZNHZ CH CHO CH C H CHzNHz CHFCHO CH (C 16H33 CH NH Compounds of Formula II that may be used in the practice of this invention are disubstituted chloro-, bromo-, or fluoro-phosphates or thiophosphates where the R and R substituents may be dimethyl, diethyl, dibutyl, diisobutyl, di-2-ethylhexyl, didodecyl, dioctadecyl, ethylene, trimethylene, propylene, dicyclopentyl, dicyclohexyl, diallyl, dioctadecenyl, di-ll-undecenyl, dibenzyl, di-butylbenzyl, di-octylbenzyl, di-alpha-methyl benzyl, di-(pchlorobenzyl), di-phenethyl, diphenyl, di-(p-chlorophenyl), di-(2,4-dichlorophenyl), di-(o-bromophenyl), di-(pnitrophenyl), di-alpha-naphthyl, di-tolyl, di-butylphenyl, di-t-butylphenyl, di-t-octylphenyl, di-nonylphenyl, di-(dodecylmethylbenzyl), di-dodecylphenyl, or di-(p-phenylphenyl).

The compounds of this invention range from mobile oils through waxes to solids. They are useful as pesticides, corrosion inhibitors, antioxidants, plasticizers, flame-proofing materials, and constituents of extreme pressure lubricants.

The heterocyclic portions of the compounds of this invention impart valuable and unexpected properties. They impart particular solubility relationships varying widely dependent upon the substituent groups. They are reactive in the presence of acid, leading to coupling reactions with other resins and substrates such as cellulose, rayon, wood, paper, and other natural and synthetic polymeric materials. They impart special and unpredictable degrees of physiological activity in both plants and animals. They are also active in other ways too numerous to mention, depending on surrounding conditions or environment.

In the following examples, which are illustrative of the invention, the parts given are by weight unless otherwise specifically stated.

Example 1 Diethyl chlorophosphate, 86 g. (0.5 mole), is added slowly with stirring to a solution of 87 g. (1.0 mole) of Z-aminoethyl vinyl ether in 250 ml. of benzene cooled to 0 to 5 C. The addition is carried on through 1 /2 hours, and the mixture is then stirred an additional hour. The amine hydrochloride precipitates and is removed by filtration with the help of celite, a filter-aid. The filtrate is washed with cold salt water, dried with anhydrous magnesium sulfate and concentrated by stripping at reduced pressure at room temperature. The product is dark red and has an odor of acetaldehyde. It contains 6.2% nitrogen and 13.2% phosphorus. The theoretical values for the diethyl ester of Z-methyl-1,3-oxazolidine-3-phosphonic acid are 6.02% nitrogen and 13.9% phosphorus. This procedure tends to leave small amounts of the amine hydrochloride as an impurity in the product. The last traces of this impurity is ditficult to remove and, unless removed, it apparently contributes a slight degree of instability to the product. The procedure of Example 2 which employs an inorganic base as the hydrogen chloride acceptor avoids this difliculty and the product obtained has far greater purity and good stability.

4 Example 2 Diethylchlorophosphate, 86 g. (0.5 mole), is added slowly with stirring to a mixture composed of potassium carbonate, 35 g. (0.25 mole), water, 35 g.; toluene, 150 ml. and 2-aminoethyl vinyl ether, 44 g. (0.5 mole) at 5 to +5 C. The reaction mixture is agitated for several hours at 0 to 5 C. after the addition is completed, and it is then filtered. The organic layer is dried with anhydrous magnesium sulfate; the drying agent is removed and the liquid concentrated by stripping at reduced pressure to give 87.5 g. of light red product containing 6.3% nitrogen and 13.7% phosphorus corresponding closely to the diethyl ester of 2-methyl-1,3-oxazolidine-3-phosphonic acid of the Formula V:

V HzC CH:

O NP(O)(OC:H5)2

This material is useful to impart flame-resistance to cellulosic materials, such as cotton, wood, viscose and rayon. Cotton fabric padded so as to retain 10% by weight of the product described above has reduced flammability and does not support combustion.

Example 3 By the procedure of Example 2 and replacing the 2- aminoethyl vinyl ether entirely with 0.5 mole of 3-aminopropyl vinyl ether, there is obtained a related product; namely, the diethyl ester of 2-methyltetrahydro-1,3,oxazine-3-phosphonic acid of the structure of Formula VT:

VI H2 (a) There is condensed one mole of dimethyl chlorophosphate and one mole of Z-aminobutyl vinyl ether by the procedure of Example 2. The product, isolated as a reddish oil, has the structure corresponding to the diethyl ester of 2-methyl-4-ethyl-1,3-oxazolidine-3-phosphonic acid.

(b) In place of the Z-aminobutyl vinyl ether of part (a) there is wholly substituted 2-amino-1-hexadecylethyl vinyl ether and the condensation efi'ected in the same manner. There is thus obtained an amber-colored waxy solid that is soluble in petroleum oils. When added to such oils in amounts of from 0.5 to 2%, the product, namely the diethyl ester of 2-methyl-5-hexadecyl-1,3- oxazolidine-3-phosphonic acid improves the resistance of such oils to oxidative degradation.

(0) By the procedure of Example 2, there is condensed dicyclohexyl chlorophosphate and 1-phenyl-2-aminoethyl vinyl ether in equirnolar amounts at 30 to 40 C. to give the dicyclohexyl ester of Z-methyI-S-phenyl-LB- oxazolidine-3-phosphonic acid. This material is useful as an oxidation inhibitor for lubricating oils.

Example 5 Diallyl chlorophosphate and 1-vinyl-2-aminoethyl vinyl ether are condensed at -l0 to 0 C. by the procedure of Example 2 to give the diallyl ester of 2-methyl- S-vinyl-1,3-oxazolidine-3-phosphonic acid;

This material is mixed with 5% by weight of di-tertbutyl peroxide and heated at C. for six to ten hours. The resultant casting is transparent, hard and flame-resistant.

Example 6 (a) Didodecyl chlorothiophosphate is condensed with Z-amino-I-methylethyl vinyl ether at 30 to 50 C. by

5 the procedure of Example 2 to'give the di-(dodecyl) ester of 2,5-dimethyl-1,3-oxazolidine-3-thiophosphonic acid/ This material is useful asan antioxidant when added to cutting oils at 0.1 to 2.0% by weight. (b) In the same way, dioctadecenyl chlorophosphate is condensed with 2-amino-l-cyclohexyl-ethyl vinyl ether.

(a) Di-p-chlorophenyl chlorothiophosphate is condensed with 3-aminopropyl vinyl ether at 50 to 80 C. by the procedure of Example 2 to give the di-(p-chlorophenyl) ester of 2-methyl-3-tetrahydro-1,3-oxazine-3- thiophosphonic acid.

This material is useful as a contact insecticide against bean aphids at from 3 to 8 lbs./ 100 gallons of spray.

The compound is compatible with polyvinyl chloride resins and may be added in amounts of 10 to 30% to improve flexibility and increase stability.

(b) In the same way, di-(p-chlorophenyl)-chlorothiophosphate is condensed with 3-amino-3-methyl-propyl vinyl ether. The product, the di-(p-chlorophenyl) ester of 2,6-dimethyl-tetrahydro-l,3-oxazine-3-thiophosphonic acid, is also valuable as an insecticide.

Example 8. e

' 1,3-oxazo1idine-3-phosphonic acid.

This product is useful as a plasticizer in amounts 20% to 40% for polyvinyl chloride resins and imparts good low temperature flexibility and resistance to ageing. The corresponding ditolyl ester is also useful in this application.

e (d) In the same'way as in part (0) hereof, one mole of diphenyl chlorophosphate and one' mole of 2-amino-lvinyl-ethyl vinyl ether are condensed to form the diphenyl ester of Z-methyl-S-vinyl-1,3-oxazo1idine-3-phosphonic acid. It may be used as a plasticizer or it may be copolymerized with other ethylenically unsaturated comonomers, such as ethylacrylate.

Example 9 0,0-ethylene chlorophosphate and 3-aminopropyl vinyl ether are condensed at 0 to C., by the procedure of Example 2 to give the product of the following i 1 structure (Formula VII):

This compound is useful as a'flame-proofing agent for cotton fabrics and other cellulosic materials.

Examples 2 and 3 are each particularl y useful as cog reactants with water-soluble condensation resins such as urea-formaldehyde, melamine-formaldehyde, phenol-formaldehyde and the like. Admixed with such condensation resins in amounts of 50 to 90% and catalyzed with acetic substances, such as sulfuric acid, ammonium chloride, ethanolamine hydrochloride and the like, the amidophosphates of Examples 2, 3, or 9 can be used to treat paper, wood, textiles and other materials to give durable, flame-proof coatings, finishes or impregnates.

It is to be understood that changes and variations may be made without departing from the spirit and. scope of the invention as defined in the appended "claims,

I claim:

l. A composition having the structure of the formula where n is an integer having a value of l to 2, X is selected from the group consisting of oxygen and sulfur, R is selected from the group consisting of hydrogen, cyclo hexyl, vinyl, phenyl, and alkyl groups of l to 16 carbon atoms, R is selected from 'the group consisting of hydrogen, methyl, and ethyl, R and R are selected from the group consisting of (1) separate groups selected individua'lly from the class consisting of cyclohexyl; alkyl and alkenyl groups of l to 18 carbon atoms; phenyl, halophenyl, benzyl, and alkyl benzyl groups of 610 20 carbon atoms, and (2) a single saturated alkylene group of 2 to 3 carbon atoms forming with the O'PO-- link -j,

to 18 carbon carbon where R and R are alkyl groups having 1. to 18 carbon i atoms.

phosphonic acid.

6. The diethyl ester of Z-methyI-tetrahydro-IB oxazine f phosphonic acid.

oxazolidine-3-phosphonic acid.

I The product of Example 9 as well as the products of jfi-thiophosphcnic acid.

10. A method comprising reacting a compound of the formula ture of the formula CHFCHOCH(R) (CH CH(R )NH where R, R, and n areas defined inclaim 1, to produce a reaction product having the structure of the formula defined in claim 1.

11. A method as defined in claim 10 in which the reaction is effected at 10 C. to 100 C. in the presence of a "basic acceptor for the halogen halide liberated.

8 References Cited in the file of this patent UNITED STATES PATENTS Engelmann Jan. 7, Georges Apr. 1, Bishop June 1, Kropa et a1. Aug. 29, Rowland Sept. 25, DazZi Aug. 24, Morris et al. Apr. 12,

OTHER REFERENCES Audricth et al.: J. Am. Chem. Soc., vol. 64, pp. 1337-9 Saunders et al.: J. Chem. Soc. (London), vol. 1948, 

1. A COMPOSITION HAVING THE STRUCTURE OF THE FORMULA 